Keysight Technologies X Series Service Manual page 327

L.O. Synthesizer/Reference Troubleshooting
A16 Reference Assembly Troubleshooting
Serial Prefix < MY/SG/US5648
The diagnostic LEDs are located near the oven oscillator near the right side of
the board. Refer to
their status indicates.
Table 8-5 LED Activity
LED Number Description
DS1 When Program Code is Loading
DS2 When 4.8 GHz Frequency is Low
DS3 When 4.8 GHz Frequency is High
DS4 Is the 4.8 GHz Reference PLL Locked?
DS5 Is the 4.8 GHz Vtune Optimized?
DS6 Is the 100 MHz PLL Unlocked?
DS7 Is the 100 MHz PLL Locked?
DS8 Is the 100 MHz Out being properly
Detected?
DS9 Opt. PFR Out Enabled
Keysight N9010A EXA Service Guide
Figure 8-10. Table 8-5
Status
On=Loading code from EEPROM
Off=Ready
On=Fault (Output Frequency too low)
Off=Normal
On=Fault (Output Frequency too high)
Off=Normal
On=Normal
Off=Fault
On=Vtune centered in range
Off=Vtune off center. No real fault
On=Fault
Off=Normal
On=Normal
Off=Fault
On=Normal
Off=Fault
On=Internal PFR enabled
Off= Internal PFR disabled (Ext. Ref. Mode)
lists the diagnostic LEDs and what
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